It is known to attach blades to vehicles for earth and snow removal, conditioning, and shaping operations. Typically, the blade comprises a concave blade body, customarily denominated the moldboard, extending transversely or slightly angled across the direction of vehicle travel. The blade is attached to the body or frame of a vehicle and is disposed in front of, underneath, or behind the vehicle, where it engages and digs into the surface worked on to move the surface substrate in a desired direction. Most often, the blade is fabricated of steel or other relatively hard material so that it is not damaged by rocks, wood, artifacts and man made debris, and various objects routinely found on the ground or in a road bed. When used for plowing or scraping, the blade is capable of leaving a substantially smooth surface. Examples of such apparatus may be found in, for example, U.S. Pat. No. 4,521,980 to Solaja, issued Jun. 11, 1985, which discloses an attachment for a loader wherein the loader can additionally perform the function of a grader. The attachment comprises an elongated body member, a lateral slot in the body member for engagement with a bucket of a loader, and a blade extending laterally of the body member.
U.S. Pat. No. 5,775,012 to Hockensmith, issued Jul. 7, 1998, teaches a hitch adjustable rear blade hitched to the back of a tractor for earth grading operations. The blade has an elongated cylindrical skid releasably mounted to the back of the blade adjacent the leading edge of the blade and a pair of spaced apart stabilizer springs adjustably mounted to the front of the blade holding the blade in tension.
U.S. Pat. No. 5,265,975 to Scott, issued Nov. 30, 1993, shows a combination scarifier/grading device comprising a scarifier having a plurality of scarifying teeth, a grading blade having a mold board and a cutting edge, and a second frame interconnecting the scarifier frame and the blade in mutually spaced apart relation with the scarifier in operably leading relation and the blade in operably trailing relation. The scarifier includes height-adjusting means for selectively raising and lowering the scarifying teeth relative to the cutting edge. The height-adjusting means comprises an at least one hydraulic cylinder.
On a much larger scale, graders prepare road surfaces to grade. However, graders leave tire tracks in gravel and new asphalt, so it is also well known to employ rakes to smooth and level tire tracks made by road construction equipment on gravel and asphalt surfaces. The blades discussed immediately above are not well-suited for this task, so it invariably falls on road crews to do the work manually. Most disturbingly, because of the nature of the work, road crew assigned to the task of raking track marks typically ride on the rear of the grader, both during operations in the field and while traveling to and from the work site. This is dangerous and, less obviously, needlessly labor intensive and expensive: needlessly because an automated rake would eliminate the need for (typically) two manual laborers.
The foregoing patents reflect the current state of the art of which the present inventor is aware. Reference to, and discussion of, these patents is intended to aid in discharging Applicant's acknowledged duty of candor in disclosing information that may be relevant to the examination of claims to the present invention. However, it is respectfully submitted that none of the above-indicated patents disclose, teach, suggest, show, or otherwise render obvious, either singly or when considered in combination, the invention described and claimed herein.
Accordingly, it remains desirable to provide an inexpensive and simple method and apparatus for mechanically raking and smoothing grader or other vehicle tire tracks created during road grading operations.